Up to 5 inches long, hornworms are the larvae of large brown moths that fly like hummingbirds. Both tomato and tobacco hornworms are green with diagonal white stripes; the horn, at the pest’s rear, is black on the tomato hornworm, red on the tobacco hornworm. The caterpillars feed upside down on leaf undersides. Since they blend into the foliage, they can be hard to spot, although the black pellets they excrete are plainly visible.
Target: Tomatoes, eggplant, potatoes, pepper, and other tomato-family plants.
Damage: Stems are stripped bare of leaves; fruit may be gnawed.
Life cycle: Moths lay pale green eggs singly on leaf undersides. After feeding, the caterpillars enter the soil and form brown, shiny, 2 inch long pupae with a handlelike projection. The pupae can overwinter. There are one to four generations a year.
Control: hand picking, tilling (pupae).
Notes: Braconid wasps parasitize hornworms. If you see worms with tiny white cocoons on their backs, let the wasps finish them off.